Considerable attention has been directed to intravenous delivery of fluids to patients, such as saline solutions and the like, in the last several years. Initially, such materials were administered to a patient by means of gravity flow from a container containing the liquid to be delivered. A difficulty encountered with such devices was that administration by gravity flow often required that the container for the liquid to be transmitted to the patient had to be positioned at a considerable elevation above the patient. Further, attempts to accurately regulate the flow of such devices proved difficult because of the fact that the pressure causing the flow of the liquid to the patient decreased as the liquid level within the container was reduced during the delivery operation.